The present invention is directed to an apparatus for use in aerating water in a container, and more particularly, to an improved aeration system for use with livewells commonly fitted in fishing boats.
In recent years, there has been an ever-increasing interest in sport fishing. The most common competition format used in sport fishing is one called "catch and release" where the contestants are permitted to fish for a certain period of time and the fish caught during the competition are compared among the various contestants to determine a winner and then released. In almost all competition today, the fish must be alive and undamaged at the end of the competition in order to qualify. Therefore, there is a need for a safe and effective aeration system to maintain proper oxygen levels within the livewell of the fishing boat in which the caught fish are held during the competition.
A variety of such aeration devices have been used in the past, but none has proven entirely satisfactory. Most aeration systems have used an aerator pump to either draw fresh water from the outside of the boat or to recirculate livewell water through a spray nozzle above the livewell water level. The high velocity water passing through the spray nozzle creates turbulence on the surface of a livewell which entrains air for oxygenation. In the simplest aeration systems a transom mounted pump draws fresh water and sprays it into the livewell. Most of the oxygenated water is lost out of the overflow because only the surface layer of water within the livewell is oxygenated. Some improvement has been achieved in other prior art devices by adding a second pump to just recirculate the livewell water through the spray nozzle. This has helped to move and cool the lower water levels within the livewell, but oxygenization is still mostly limited to the surface water. Also, spray nozzles generally create large bubbles which rise quickly and are less efficient than small bubbles in the oxygenation process.
Other prior art devices are also known which include the use of a relatively expensive air pump system to provide substantial amounts of oxygen to the livewell. These air pumps, however, are expensive, noisy and subject to failure under heavy use and boat vibration. These air bubble systems also require air tubing and either a porous stone or perforated ring on the bottom of the livewell to distribute the air in small bubbles.